Imprinting and obliterating apparatus



Jan. 14, 19 9,

Filed July 6, v1966 0 F I j INVENTORS VICTO SPRET MAX ONFELD ATTORNEYSUnited States Patent 3,421,611 IMPRINTING AND OBLITERATING APPARATUSVictor Spreter, 29 Rue Sautter, Geneva, Switzerland, and

Max Schonfelder, 17 Chemin-des-Paquerettes, Petit- Laucy, Geneva,Switzerland Filed July 6, 1966, Ser. No. 563,130 U.S. Cl. 19749 Int. Cl.B412 1/32 9 Claims ABSTRACT OF THE DISCLOSURE This invention relates toan apparatus for visibly imprinting, especially by impact printing, aninscription base cooperating with an inking ribbon, and for successivelyobliterating the inscription in a re-usable way.

It is known that impact printing by means of an inking ribbon on a papersheet is generally carried out in such a way that ink permeates thepaper. Such a paper writing base is usable just once.

Stencil writing bases are also known, which are made of paper coveredwith paraffin to permit reproduction of impact imprinted inscriptions.By using such writing bases, obliteration of the inscription can beeffected by means of a suitable solvent, but a repeated re-use of thewriting base cannot be achieved in practice.

Re-usable writing bases, by which a temporary inscription is obtainable,have already been proposed, wherein a transparent sheet is brieflyforced into contact with a sheet coated on one side with a waxy layer.However, such writing bases are subject to a rapid deterioration and arenot advantageously employable in impact printing systems. 1

It is a chief object of the invention to provide an apparatus forvisibly imprinting, especially by an impacting force, a transparentsheet assembled to an inking ribbon, and for successively obliteratingthe inscription in a reusable way. Other objects of the presentinvention will become more apparent from the following detailed description and appended claims.

According to the present invention, an imprinting and obliteratingapparatus is proposed, comprising: an inking ribbon having absorbedthereto a non-diffusable ink; an inscription base having at least asmooth surface not permeable by said ink; inscription means for forcinginto contact said inking ribbon and said smooth surface for transferringink to said base to make a visible impression thereon; and obliteratingmeans consisting of an elastic member engaging a small area of saidribbon and applying said area under a given pressure against the part ofsaid surface carrying said visible impressions, and means imparting anoscillatory movement to said elastic member for rubbing said areaagainst said part of said surface to reabsorb said transferred ink.

The invention is described in greater detail by reference to the singlefigure of the drawing which is a schematic view of an apparatusembodying the invention.

A preferred imprinting and obliterating apparatus embodying theinvention comprises an endless inking ribbon 1 passing around the guideroll 2, the driving roll 3 and the obliterator roll 4 which is made ofspongy caoutchouc and is mounted on axis 5. The inking ribbon 1 containsice absorbed thereto a non-ditiusable ink, i.e. a non-percolating one.

The guide rolls 7, 8 and 9 and the driving roll 10 engage an endlesstransparent band 6 of hard plastic material, e.g. of a polyester such aspolyethylene terephthalate, which serves as the inscription base. Asshown in the drawing, roll 4 as well as rolls 2, 3 and 7 to 10 arearranged so that the bands 1 and 6 each show a rectilinear portionpassing across two imprinting members, one of which is the type-carryingmember 11 facing the inking ribbon 1, and the other the platen member 12facing the band 6.

Control means of a conventional type and therefore not shown in thedrawing are employed for activating the imprinting members 11 and 12 aswell as for the driving rolls 3 and 10.

The driving rolls 3 and 10 both assure the transport of bands 6 and 1 inthe direction of arrow A. The control of the driving rolls 3 and 10 isconnected to the control of the imprinting members 11 and 12 in such away that 'both bands are advanced a given length during the timecomprised between two following imprinting operations.

Inscription is eifected by forcing into contact bands 6 and 1 against apreselected symbol of the type-canying member 11 by means of the platenmember 12.

In order to facilitate the reading of the visible impression thusdeposited on the inner surface of band 6, this band is then conveyed, asindicated by arrow B, through a light-coloured reading screen 13 whichproduces a clear contrast for the ink deposited from hand 1.

Regeneration of the imprinted transparent sheet forming the band 6 iseffected by placing it again into contact with the inking ribbon 1 bymeans of the obliterator roll 4 which presses band 6, under a givenpressure, against a support member 14.

An auxiliary endless band 15 made of plastic material and conveyed byroll 17 and guide roll 16 is passed across the support member 14 andband 6. This auxiliary band 15 is advanced in synchronism with band 6 inorder to avoid any rubbing on the outer face of the latter. The axis 5of the obliterating roll 4 is removably mounted into one of threepossible positions of the bearing arm 18, thus allowing the distancebetween the axis of roll 4 and the support member 14 to be varied inorder to properly adjust the contact pressure of roll 4 against band 6.

An eccentric member 19 controlled by means not shown in the drawingco-operates with the bearing arm 18 to impart to it, and consequently toroll 4, an oscillatory, e.g. a circular movement. The rubbing of band 1against hand 6 due to said vibratory movement of roll 4 causesreabsorption by band 1 of the ink deposited on band 6 and, therefore,obliteration of the visible impressions and recovery of the depositedink.

According to the experiene it has been demonstrated that the abovedescribed device permits 300 characters per minute to be easilyimprinted and obliterated, when the circular movement of theobliterating roll has a frequency of about rpm. A very satisfactoryobliteration is obtained when the contact pressure of band 6 againstband 1 is in the range from about 4 to 6 p.s.i.

The reading screen 13 is provided with grooves (not shown in thedrawing) for guiding the edges of band '6, thus avoiding direct contactof the inscription with the screen and its consequent obliteration.

Depending on the structure and function of the apparatus which thedevice of the present invention has to be employed, modifications may bedevised, especially with regard to the form and the structure of theinscription band. It is thus apparent that the band can be formed of anysuitable material having the properties required by the invention,namely a smooth surface not permeable by ink, e.g. a glass surface, ametal surface etc.

The inscription base will be a transparent one only in the case where areading of the inscription through the base is desired.

Furthermore, the number of the obliterating members and their rubbingmovement will depend on the desired inscription speed.

This rubbing movement can be other than a circular one, e.g. any otheroscillatory or vibratory movement. It has to be noted that roll 4, otherthan of spongy caoutchouc, can be formed of any sufficiently elasticmaterial such as a usual caoutchouc, a spongy polyurethane composition,etc.

The inkin-g ribbon may be given the form of a Mobius tape to allow bothits faces to be utilized.

It is apparent from the above description that the apparatus of theinvention can be employed by using any known ink-transfer inscriptionmethods other than the impact printing method.

It is intended that modifications, improvements and additions of partsmay be made to the described apparatus without departing from the scopeof the invention as defined by the appended claims.

We claim:

1. An imprinting and obliterating apparatus, comprismg:

(a) an inking ribbon having absorbed thereto a nondifiusable ink,

(b) an inscription base having at least a smooth surface not permeableby said ink,

(c) inscription means for forcing into contact said ribbon and saidsmooth surface for transferring ink to said base to make a visibleimpression thereon,

(d) and obliterating means for rubbing at least a small area of saidribbon against the part of said surface carrying said visibleimpressions to reabsorb said transferred ink.

2. An imprinting and obliterating apparatus, comprising:

(a) an inking ribbon having absorbed thereto a nondiffusable ink,

(b) an inscription base having at least a smooth surface not permeableby said ink,

(c) inscription means for forcing into contact said ribbon and saidsurface for transferring ink to said base to make visible impressionsthereon,

-(d) an elastic member engaging a small area of said ribbon and applyingsaid area under a given pressure against the part of said surfacecarrying said visible impressions, and

(e) means for imparting an oscillatorymovement to said elastic memberfor rubbing said area against said part of said surface to reabsorb saidtransferred ink.

3. An apparatus as claimed in claim 2, wherein said inscription meanscomprise a type-carrying member facing said ribbon and a platen memberfacing said base.

4. An apparatus as claimed in claim 2-,=wherein said rubbing movement ofsaid ribbon is a circular movement.

5. An apparatus as claimed in claim 2, wherein said elastic member is aguide roll for said ribbon, means being provided for controlling thedistance between the rotation axis of said guide roll and said base.

6. An apparatus as claimed in claim 2, wherein said elastic member ismade of spongy caoutchouc.

7. An apparatus as claimed in claim 2, wherein said base is a bandformed of a polyester resin.

8. An apparatus as claimed in claim 2, wherein said base is transparent.

9. An apparatus as claimed in claim 2 comprising a support member facingsaid elastic member on the opposite side of said base, an endless bandengaging between said support member and said base, and means foradvancing said base and said endless band in synchronism.

References Cited UNITED STATES PATENTS 1,706,046 3/ 1929 Tisdale 35-612,098,689 11/1937 Masson 346-44 2,148,917 2/ 1939 Von Heinrich 101-1682,312,623 3/1943 Brooks et al 35-66 2,807,891 10/1957 Roscoe 118-1063,084,457 4/ 196-3 Schott 35-66 3,35 8,149 12/1967 Prei'kschat 346-213,309,989 3/1967 Solhelm et a1. 197-149 ROBERT -E. PULFREY, PrimaryExaminer.

E. H. EIOKHOLT, Assistant Examiner.

US. Cl. X.R.

